A. Field of the Disclosure
The present disclosure relates generally to the treatment of urological disorders. Methods of treating such disorders, implants for the treatment of such disorders, and methods of using said implants, are provided.
B. Background
The muscles and ligaments that form the pelvic floor serve two critical functions in female physiology: controlling the flow of urine from the bladder and maintaining the positions of pelvic organs. When the floor weakens, is injured, stretches, or atrophies, the result can be urinary incontinence (UI) and pelvic organ prolapse (POP). POP is the descending or drooping of pelvic organs, such as the bladder, uterus, vagina, small bowel, and rectum. When it occurs, POP can result in the movement of one or more pelvic organs into another organ, for example prolapse of the bladder into the vagina. Other pelvic floor disorders include vaginal prolapse, vaginal hernia, rectocele, enterocele, uterocele, and urethrocele. POP and urinary incontinence are relatively common (about 30% of women in the United States experience some degree of pelvic organ prolapse in their lifetimes, and about 12% of U.S. women aged 60-64 experience urinary incontinence on a daily basis).
Pelvic floor disorders often cause or exacerbate female urinary incontinence. One type of urinary incontinence, called stress urinary incontinence, effects primarily women and is often caused by two conditions: intrinsic sphincter deficiency (ISD) and hypermobility. These conditions may occur independently or in combination. In ISD, the urinary sphincter valve, located within the urethra, fails to close properly, causing urine to leak out of the urethra during stressful activity. In hypermobility, the pelvic floor is distended, weakened, or damaged. When the afflicted woman sneezes, coughs, or otherwise strains the pelvic region, the bladder neck and proximal urethra rotate and descend. As a result, the urethra does not close with sufficient response time, and urine leaks through the urethra.
Various techniques have been used to anchor the pelvic organs to treat prolapse and to compress or support the urethra to prevent urinary incontinence. However, the performance of these traditional surgical techniques for these purposes has been poor.
Traditionally, both of these problems were fixed by repairing the patient's own tissue defects or by placing a non-synthetic implant underneath the urethra through an abdominal incision alone or in combination with a transvaginal incision. However, these approaches had unacceptable failure rates, long surgical times, long hospital stays, and significant post-operative pain. They were also criticized for requiring the patient's own tissues for support (specifically, the periurethral and perivesical fascia), which had the disadvantages of requiring that implants be custom fitted to the specific patient's dimensions and requiring that the patient had tissues of adequate strength. In addition, this approach used grafted tissue to form the implant, which in some cases would degrade with time.
In the late 1990s a new procedure was introduced for treating incontinence involving the insertion of a sling around the urethra made of synthetic mesh. The “mid-urethral sling” gained instant popularity over traditional transabdominal approaches and graft suburethral slings. It was simple to insert; the suburethral mesh sling could be introduced through a small transvaginal incision during an outpatient procedure in less than an hour. It required only a short recovery time with less postoperative pain. The synthetic mesh maintained its integrity over time and proved to be more durable than the patient's own tissue or cadaver tissue. The previously described techniques declined in number or were abandoned.
Unfortunately the new approach proved to have serious long-term side effects. The placement of the mesh posterior to the urethra creates a situation in which the mesh can press into the vagina, causing symptoms such as dyspareunia (painful intercourse), pelvic pain, anterior vaginal thinning, and erosion of the mesh into the vagina. These side effects can only be resolved by another procedure to remove the mesh. As a result, the patient often suffers worse symptoms than she did before the first procedure.
Consequently there is a need for a transabdominal approach to using non-absorbable material to treat POP and UI without the serious risks associated with the transvaginal approach.